1. Field of the Invention
The present invention relates to a ground compacting method and apparatus and, more particularly, to a method and apparatus for the compacting of a road shoulder.
2. Description of the Prior Art
The shoulders of roads are often supplied with granular material, such as gravel or sand. Immediately after the initial distribution of such gravel or sand, the shoulders are soft and should not be subjected to the full weight of a vehicle. It is preferable to compact the material such that it forms a substantially hard surface which supports a vehicle without the material redistributing and thereby causing ruts or grooves in the shoulder.
The conventional method of preparing road shoulders consists of distributing gravel from the rear of a dump truck and then compacting the gravel with an independently driven rolling device. Unfortunately, such rolling devices are not intended for independent highway travel to and from a job site, such that they must be transported upon a larger vehicle. Additionally, time must be spent unloading and loading the rolling device from and to the larger transport vehicle at the job site.
In order to avoid the disadvantages of transporting a separate rolling device, road crews preparing a shoulder will often utilize the rear tires of the dump truck to compact the road shoulder. Unfortunately, the tires of the dump truck will often cause ruts within the freshly distributed shoulder material. Additionally, given the limited width of conventional truck tires, several passes are often required in order to adequately compact the shoulder material.
While attempts have been made to solve the aforementioned problems in compacting road shoulders, none have provided an apparatus for efficiently and safely preparing the shoulder of a road without requiring independently driven pieces of equipment. For example, U.S. Pat. No. 4,193,710 discloses a roller centrally mounted to the front of a dump truck. The roller may be vertically moved into and out of engagement with a road surface. While such an apparatus may be adequately used for compacting a road surface, it is not intended to efficiently compact a shoulder adjacent the road surface. The shoulders of roads are often positioned immediately adjacent ditches or gullies such that positioning a roller which is centrally mounted to a truck on the shoulder will result in the tires along one side of the truck being positioned on a steep embankment. This leads to instability of the truck, thereby jeopardizing the safety of the road crew members located therein or adjacent thereto. Furthermore, since the wheels of one side of the truck may be positioned on the embankment below the wheels of the other side of the truck, the roller may often be disposed in non-parallel relation to the shoulder resulting in uneven compacting of the shoulder material.
Accordingly, there is a need for a method and apparatus for compacting a ground surface including a vehicle which does not need to leave the road surface while compacting the shoulder of the road. Further, there is a need for such an apparatus which includes an applicator for spreading granular material, preferably gravel, on the ground which is then compacted.
The present invention provides a method and apparatus for compacting a road shoulder by a vehicle traveling along a road without requiring the vehicle to leave the road surface and contact the shoulder.
The apparatus of the present invention includes a compactor support structure having at least one mounting bracket detachably mounted to the front end of a vehicle. The compactor support structure supports a compactor having an engagement surface for compacting the shoulder. The compactor is adapted for both vertical and horizontal movement relative to the vehicle such that it may be moved from a rest position adjacent the longitudinal center axis of the vehicle and above the road to an operative position positioned outwardly from the longitudinal center axis and in engaging contact with the shoulder.
The at least one mounting bracket of the compactor support structure is removably supported by a conventional accessory mount of the truck. The compactor support structure includes a guide member which slidably receives a horizontally movable ram. A first, or ram, linear actuator interconnects the guide member to the ram wherein activation of the ram linear actuator causes horizontal movement of the ram. The first ends of a pair of laterally spaced arms are pivotally supported by the ram. Second ends of the pair of arms support the compactor, preferably a rotatably mounted roller. A pair of second, or arm, linear actuators connect the second ends of the arms to the ram wherein activation of the arm linear actuators causes pivoting movement of the arms. As the arms pivot, the roller is moved in substantially vertical movement.
A control unit controls the operation of the ram and arm actuators and is supported by the guide member. A pendant controller communicates with the control unit wherein an operator in the cab of the vehicle may manipulate the pendant controller thereby causing activation of the actuators and corresponding movement of the roller.
The apparatus of the present invention also preferably includes a material applicator connected to the rear end of the vehicle in spaced relation to the roller. The material applicator includes a spreader for distributing granular material, preferably gravel, which is later compacted by the roller. As such, a single apparatus may be used to efficiently apply and compact material along a road shoulder.
The method of the present invention includes distributing a granular shoulder material, preferably gravel, along the shoulder of a road from an applicator supported by a vehicle positioned on the road surface. Next, an actuator is activated for moving a ram supporting a roller horizontally outwardly from a longitudinal center axis of the vehicle positioned on the road surface. The roller supported by the ram is then pivoted downwardly into engagement with the freshly distributed gravel. The vehicle next simultaneously moves in a direction from the roller to the applicator in substantial alignment with the shoulder wherein the freshly distributed gravel is compacted by the roller.
Therefore, it is an object of the present invention to provide a method and apparatus for distributing and compacting ground surfaces.
It is a further object of the present invention to provide such an apparatus which is self-transportable.
It is another object of the present invention to provide such a self-transportable apparatus having a compactor which may be retracted from an operative position to a rest position thereby permitting the vehicle to travel at ordinary speeds along a road to and from the job site.
It is yet another object of the present invention to provide an apparatus for compacting road shoulders while traveling along a road but not along the shoulder.
It is a further object of the present invention to provide such an apparatus which is flexible in attaching to conventional accessory brackets on the front of vehicles.
It is still yet another object of the present invention to provide a single apparatus for the distribution and compacting of road shoulder materials.